Argentina forward Aguero scored twice in the first half against West Bromwich Albion before setting up the third for Ilkay Gundogan, who also grabbed the final goal in City's 4-0 win at the Hawthorns.

It was a welcome result for City boss Guardiola, who had gone six games in all competitions without a win.

Sergio Aguero scored a brace to help Manchester City end six-game winless run. AFP

City remain top of the Premier League on goal difference ahead of Arsenal despite their recent struggles and they can now look forward to Tuesday's Champions League clash against Barcelona with more confidence.

Aguero's double took his tally to 13 goals this season and he will chase his 150th for City when Guardiola's former club visit Eastlands this week.

After dropping Aguero for City's 4-0 defeat at Barcelona recently, Guardiola was delighted with the contribution of the former Atletico Madrid star.

"Sergio is a special player. But I would like to convince him how important he is for us," Guardiola said.

"We need him a lot and when he's in that mood and shows that hunger, Sergio is definitive.

"He's an important part of this club and we want to try to help him to become a bigger and bigger part of this fantastic club.

"Sergio is so important for us. We don't have too many strikers -– we have Sergio and Kelechi (Iheanacho) but he's too young and he has to learn a lot."

Aguero was sacrificed for tactical reasons in the first meeting with Barca, but Guardiola admitted his talisman has earned his place in the team for the return.

Asked if the marksman will start against Barcelona, he said: "I think so! But I'm not going to tell you which position!"

No excuses

Guardiola was also pleased with Gundogan after the German playmaker netted his first brace in English football.

"Sergio scored two but so did Gundogan. He has the qualities with the ball in the middle, he's safe and he's really good with the ball one against one attacking central defenders," Guardiola said.

"He showed that with the first goal with the pass to Sergio."

Guardiola admitted City needed to end their winless run -– so they didn't lose their heads.

"I was very pleased -– after six games we needed a win for the head (minds)," he added.

"The problem when you haven't won for six games is you lack a bit of confidence for the next one.

"That happened in that period but we played well. But when you don't win, your argument about how many good things you did sound like excuses.

"When we win you're right, when we don't, you just look for excuses.

"That's why it was so important to win the game and I was very pleased with our performance in the first half.

"We won 4-0 but in the second half West Brom showed how good the Premier League is.

"For me it was difficult to understand why we had control in the first half, and then we didn't in the second half with the same players.

"At 60, 65 minutes, anything could have happened, but the moment Ilkay Gundogan scored the third goal, the game was almost over."

West Brom assistant head coach Dave Kemp admitted they couldn't live with Aguero.

"Aguero's two goals were tremendous. You know he's a good player but you hope he's off colour a little bit. He wasn't, and you find yourself in trouble," Kemp said.

"If something isn't quite right they're good enough to be all over you like a rash - as they were.

"Sometimes you have to hold your hand up. If you're playing a lesser team sometimes you get away with it. Not against these."